Featured Research

First Dinosaur Embryo Skin Discovered -- Unhatched Embryos Are First Ever Found Of Giant-Plant Eating Dinosaurs

Date:

November 18, 1998

Source:

American Museum Of Natural History

Summary:

A team of researchers have announced the discovery of a dinosaur nesting ground strewn with thousands of eggs, dozens of which still have unhatched dinosaur embryos inside. In addition to tiny embryonic bones, many of the eggs contain patches of delicate fossilized skin, providing the first glimpse of the soft tissue covering baby dinosaurs.

Share This

November 17, 1998...A team of researchers announced today in the journal Nature the discovery of a dinosaur nesting ground strewn with thousands of eggs, dozens of which still have unhatched dinosaur embryos inside. In addition to tiny embryonic bones, many of the eggs contain patches of delicate fossilized skin, providing the first glimpse of the soft tissue covering baby dinosaurs.

Related Articles

The extraordinary new fossils represent a number of scientific firsts: the first dinosaur embryos to show fossilized skin; the first known embryos of the giant plant-eating dinosaurs called sauropods; and the first dinosaur embryos found in the southern hemisphere. As well as appearing in Nature, the discovery is also featured in the December issue of National Geographic.

The nesting site, which dates from the late Cretaceous and is approximately 70 to 90 million years old, is located near Auca Mahuida, in the Patagonian badlands of Argentina. The research team, headed by scientists from the American Museum of Natural History in New York City and the Museo Municipal Carmen Funes in Neuquén, Argentina, named the new site "Auca Mahuevo" for its tremendous abundance of eggs, or huevos in Spanish. Eggs are so plentiful in the square-mile nesting site that it is virtually impossible to walk without crushing egg shell fragments under foot.

If the tiny embryos from Auca Mahuevo had hatched, the baby dinosaurs would have started life a mere fifteen inches long and grown to an adult size approaching forty-five feet long. The fossil skin reveals a scaly surface, much like the skin of a modern-day lizard. One of the fossils has a distinct stripe of larger scales near its center, which probably ran down the animal's back.

Why Auca Mahuevo yields two of the rarest of all types of fossils, fragile embryonic bones and skin casts, is one of the mysteries about the site that the team hopes to answer. Initial studies suggest that the egg clusters were laid in the floodplain of ancient streams that periodically overflowed, burying the unhatched eggs on its banks in a layer of mud. The covering of silt protected the eggs, and some of their contents, from scavengers and disintegration by the elements. Repeated cycles of egg laying and flooding could have produced the super-abundance of fossil eggs and embryos found by the team.

Given the number of egg clusters at Auca Maheuvo, hundreds, if not thousands, of giant sauropod dinosaurs must have gathered there to lay their eggs. The nesting site probably would have stretched for miles in a valley created by a series of shallow streams. However, the fossils do not reveal whether the adult dinosaurs cared for their young, or even if they made well-formed nests. It is not possible to determine precisely which kind of sauropod dinosaurs laid the eggs at Auca Maheuvo, but the discovery of tiny teeth in the eggs provides an intriguing clue. One embryo alone has at least 32 individual pencil-shaped teeth, each small enough to fit easily into the capital "O" at the beginning of this sentence. The only sauropod dinosaurs alive at the end of the Cretaceous period with teeth this shape were sauropods known as titanosaurs. The remains of these dinosaurs are common near Auca Maheuvo, making it very likely that the embryos belong to this group.

Unlike any other known sauropods, titanosaurs had bony, armored plates embedded in their skin. The embryo's skin, however, does not show any signs of armored plates, indicating that these grew only after the dinosaurs had hatched. This growth pattern mirrors that seen in modern armored lizards and crocodiles, the juveniles of which lack the bony patches in the skin that are present in adults.

The co-leaders of the expedition are: Luis M. Chiappe, research associate, American Museum of Natural History; Rodolfo A. Coria, director, Museo Municipal Carmen Funes; and Lowell Dingus, research associate, American Museum of Natural History and president, InfoQuest Foundation. Other authors of the Nature paper announcing the discovery are Frankie Jackson, research associate, Museum of the Rockies, Montana State University; Anusuya Chinsamy, assistant professor, University of Cape Town; and Marilyn Fox, preparator, Division of Vertebrate Paleontology, Peabody Museum of Natural History, Yale.

The research received primary support from the National Geographic Society, InfoQuest Foundation, and the Dirección General de Cultura (Gobernación de la Provincia del Neuquén, Argentina).

American Museum Of Natural History. (1998, November 18). First Dinosaur Embryo Skin Discovered -- Unhatched Embryos Are First Ever Found Of Giant-Plant Eating Dinosaurs. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/1998/11/981118081844.htm

Featured Research

Mar. 3, 2015 — The precise dating of ancient charcoal found near a skull is helping reveal a unique period in prehistory. The Manot Cave, a natural limestone formation, had been sealed for some 15,000 years. It was ... full story

Mar. 2, 2015 — Richard III is the only male to be discovered at infamous former car-park site. A mysterious lead coffin found close to the site of Richard III's hastily dug grave at the Grey Friars friary has now ... full story

Mar. 1, 2015 — A study of how climate change has affected emperor penguins over the last 30,000 years found that only three populations may have survived during the last ice age, and that the Ross Sea in Antarctica ... full story

Feb. 27, 2015 — That swim tracks made by tetrapods occur in high numbers in deposits from the Early Triassic is well known. What is less clear is why the tracks are so abundant and well preserved. Paleontologists ... full story

Feb. 27, 2015 — DNA evidence shows surprise cultural connections between Britain and Europe 8,000 years ago. Researchers found evidence for a variety of wheat at a submerged archaeological site off the south coast ... full story

Feb. 26, 2015 — The miniweight boxing title of the animal world belongs to the mantis shrimp, a cigar-sized crustacean whose front claws can deliver an explosive 60-mile-per-hour blow akin to a bullet leaving the ... full story

Feb. 24, 2015 — Thirteen million years ago, as many as seven different species of crocodiles hunted in the swampy waters of what is now northeastern Peru, new research shows. This hyperdiverse assemblage, revealed ... full story

Feb. 24, 2015 — Tropical turtle fossils discovered in Wyoming reveal that when Earth got warmer, prehistoric turtles headed north. But if today's turtles try the same technique to cope with warming habitats, they ... full story

Feb. 24, 2015 — A French-Kenyan research team has just described a new fossil ancestor of today's hippo family. This discovery bridges a gap in the fossil record separating these animals from their closest ... full story

Feb. 24, 2015 — Climate-driven plague outbreaks in Asia were repeatedly transmitted over several centuries into southern European harbors, an international team of researchers has found. This finding contrasts the ... full story

Related Stories

Apr. 18, 2013 — A small, bird-like North American dinosaur incubated its eggs in a similar way to brooding birds -- bolstering the evolutionary link between birds and dinosaurs, researchers have ... full story

Jan. 23, 2012 — An excavation at a site in South Africa has unearthed the 190-million-year-old dinosaur nesting site of the prosauropod dinosaur Massospondylus -- revealing significant clues about the evolution of ... full story

Jan. 23, 2012 — An excavation at a site in South Africa has unearthed the 190-million-year-old dinosaur nesting site of the prosauropod dinosaur Massospondylus -- revealing significant clues about the evolution of ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.